1. Field of the Invention
The present invention relates to a magnetic recording and/or reading apparatus. More particularly, the present invention relates to a magnetic recording and/or reading apparatus including a power transmitting gear to transmit power from a loading motor to drive components driven during loading and unloading of magnetic tape.
2. Description of the Related Art
In general, magnetic recording and/or reading apparatuses record information on and/or read information from a recording medium such as magnetic tape. Examples of the magnetic recording and/or reading apparatuses include video cassette tape recorders (VCRs), camcoders, and the like. Typical magnetic recording and/or reading apparatuses generally comprise a head drum installed on a main chassis, a loading motor, a capstan motor, and a pair of reel assemblies on which a cassette tape is placed.
The loading motor drives a main gear to power several components of the magnetic recording and/or reading apparatus coupled to the main gear to load and unload magnetic tape. For example, the main gear may drive a pole base unit, a pinch roller unit, and a brake unit.
FIG. 1 illustrates a power transmitting process of a loading motor and a main gear. Referring to FIG. 1, a loading motor 10, a power transmitting gear 20 coupled to the loading motor 10, a relay gear 32, and a main gear 34 are shown.
The power transmitting gear 20 includes a first gear 22 engaged with a motor gear 12 coupled to a shaft of the loading motor 10. Additionally, a second gear 26 engages with relay gear 32 coupled to the main gear 34, and a shaft member 24 couples the first and second gears 22, 26. The first gear 22, the second gear 26, and the shaft member 24 are formed of a general plastic material in consideration of manufacturing convenience and cost.
FIG. 2 is a cross-sectional view of the shaft member 24 of the power transmitting gear 20. As shown in FIG. 2, the shaft member 24 is bar-shaped and is preferably filled with a material such as plastic material; however, other suitable materials may be used. As described above, the power transmitting gear 20 is generally injection-molded using a plastic material in consideration of manufacturing convenience and cost. However, the shaft member 24 is susceptible to deformation due to conditions of the mold. In other words, the shaft member 24 may distort or twist due to several reasons including injection pressure, drying conditions, and the like during injection-molding. The loading motor 10 rotates at about 1,000 rpm during loading and/or unloading of the magnetic tape. Thus, directly coupling the power transmitting gear 20 to the loading motor 10 to spin is not normally desirable due to relatively serious twisting and swinging of the shaft member 24. As a result of such an arrangement, noise levels increase. In particular, abnormal noises are typically made during loading and unloading of the magnetic tape. In a case where the shaft member 24 is long, it is difficult to control swinging of the shaft member 24. As a result, levels of abnormal noise increase.
Accordingly, there is a need for an improved power transmitting gear and a method of manufacturing the power transmitting gear to reduce twisting, swinging, and noise levels during operation.